It has been discovered that mechanically alloyed (MA) dispersion strengthened alloys may become sensitized to stress corrosion cracking at room temperature after being heated to temperatures of about 100.degree. C. to 150.degree. C. or above. Samples of IncoMAP.RTM. alloy AL-905 XL (IncoMAP.RTM. is a registered trademark of the Inco family of companies), an aluminum-base MA dispersion strengthened alloy containing magnesium and lithium designed to replace alloys such as 7075-T73 in forgings where weight is critical. Samples of alloy AL-905XL, were forged, aged at 100.degree. C. for 336 hours and air cooled. It has been found that these dispersion strengthened aluminum-base alloys become sensitized to stress corrosion upon aging at 100.degree. C. After this 100.degree. C. heat treatment, samples, stressed typically at 75 percent of the yield strength, cracked after as few as 1 or 2 days in 3.5% sodium chloride. A 20 day period without cracking is a typical minimum requirement for dispersion strengthened alloys containing lithium and magnesium. It is an object of this invention to provide a method for protecting aluminum-base dispersion strengthened alloys from stress corrosion cracking after being exposed to temperatures of about 100.degree. C. to 150.degree. C.